When it comes to working out, you might think trying your best would be theway to make the most of your exercise time. But you'd be wrong. For a study at Virginia Polytechnic Institute and State University that pitted several motivational techniques against each other, researchers had 56 female undergraduates attempt to do as many sit-ups as possible in 90 seconds. Those who were given the vague directive "do your best" averaged about 43 sit-ups on each day of the four-day study. On the other hand, women assigned specific long-or short-term targets--"do 10 percent more than you did last time"--managed 56 sit-ups by the last day's session.

While previous research hasn't proven that setting concrete goals enhances athletic performance, Virginia Polytech graduate student Jeffrey Smith, M.A., believes that's because the goals set in those studies were too easy. To truly improve performance, Smith suggests, the goals we set must be difficult enough that there's a good chance we'll fail. While that approach will often deprive us of the satisfaction we feel in reaching our objective, we're likely to perform better in "failure" than we would in successfully meeting an easy goal.

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